MediumV Technology Geopolitics & AI8 October 2026, Thursday
GlobalFoundries to build first US silicon interposer supply for TSMC
GlobalFoundries said on 8 October it had signed a five-year, 2 billion dollar agreement with TSMC. The company will make silicon interposers for TSMC's CoWoS packaging at its Malta plant in New York, with volume production starting in the first half of 2028.
A silicon interposer is a thin layer of silicon that links the processor die and high-bandwidth memory inside a single package in AI accelerators. CoWoS is TSMC's advanced packaging method for building this multi-chip structure. GlobalFoundries said the agreement will establish the first US supply of silicon interposers and add new capacity at Malta. No government grant tied to the deal was announced.
According to The Register, advanced packaging is the tightest bottleneck in US chipmaking. When TSMC began producing Nvidia's Blackwell chips in Arizona in 2025, they were shipped back to Taiwan for final assembly. Amkor, TSMC's US packaging partner, is expected to bring its Arizona facility online in 2028, and TSMC's own Arizona packaging plant in 2029. Production at Malta falls in the same window.
TrendForce, in a forecast reported on 14 September, expects TSMC's CoWoS capacity to rise from about 130,000 wafers a month at the end of 2026 to 260,000 by the end of 2028. The bulk of that expansion sits at its AP7 site in Taiwan. So while capacity doubles, the US share stays close to zero until 2028. On 8 October TSMC reported record third-quarter revenue of NT$1.49 trillion.
Talay assessment
Bottom line
The deal is the first concrete piece in breaking the need for US-made AI chips to return to Taiwan for packaging. But with volume production starting in 2028, US dependence on advanced packaging will not change through 2026–2027. The likeliest path is CoWoS expansion in Taiwan outpacing that in the US, with the dependence lasting at least two more years.
Likely effects
- US chip supply chainPositive6 months+
Combined with Amkor's 2028 and TSMC's 2029 Arizona facilities, interposer output at Malta makes end-to-end AI chip production in the US possible.
- Taiwan's bargaining powerUncertain1–6 months
With the weight of capacity staying in Taiwan until 2028, the island's role as a critical supplier to the US persists over the near and medium term.
- Supply riskNegative1–6 months
With no US alternative before 2028, a disruption in the Taiwan Strait would hit the supply of AI hardware directly.
Possibilities, ranked
- 1Timeline holds55%
Interposer production at Malta starts in the first half of 2028 and lines up with the Arizona packaging plants.
Watch: GlobalFoundries announcements on Malta capacity investment and CHIPS support
- 2Delay30%
Capacity construction or the Amkor plant slips, pushing US packaging into 2029.
Watch: Quarterly timeline updates for Amkor's Arizona facility
- 3Acceleration15%
Washington pulls the timeline forward through incentives or tariff pressure, and Intel's packaging capacity steps in as a stopgap.
Watch: New Commerce Department incentives or tariff decisions on advanced packaging
Probabilities are calibrated judgement based on the sources, not measurement, and are revised as new information arrives. Not investment advice.
Market reaction
Indicators affected
- Deal value▲ $2bn
- Volume production start▲ H1 2028
Sources
- GlobalFoundries — GlobalFoundries reaches agreement to establish U.S.-based supply of silicon interposers for advanced AI packaging
- The Register — TSMC taps GlobalFoundries to bolster US silicon interposer production in $2B deal
- TrendForce — TSMC reportedly targets capacity boost, CoWoS to double by 2028